Objects are seen in three dimensions because light reflects from them and generates a light field in space. The two eyes of a viewer perceive this light field differently due to their different locations in space relative to the object, and the brain of the viewer processes the different perceptions of the light field by the two eyes to generate three-dimensional (“3-D”) perception.
Stereoscopic imaging is a technique utilized to simulate three-dimensional images to viewers. Stereoscopic displays operate by providing different yet corresponding perspective images of the same object or scene to the left and right eyes of the viewer. The viewer's mind thereby processes these two images to produce a perception of three dimensions. The principles of stereoscopic imaging have been applied to various areas for many years, including to the training of professionals, such as pilots to physicians, and to entertainment, such as 3-D movies and computer games.
All stereoscopic systems rely upon one or more techniques to segregate images for the right and left eyes. Typically, stereoscopic imaging systems utilize special parallax barrier screens, headgear, or eye wear to insure that the left eye sees only the left eye perspective and the right eye sees only the right eye perspective. These systems may include, for example, shutters on eye glasses that open or close depending on whether the image on the screen needs to be viewed by the left or right eye. However, these types of systems result in eyestrain associated with the “flicker” created by the shutter.
Additionally, U.S. Pat. No. 6,717,728, issued to Putilin et al. and commonly owned by the assignee of the present invention, discloses an autostereoscopic 3-D display that provides real-time and high resolution 3-D imaging capability without utilizing parallax barriers or specialized headgear. The Putilin et al. display utilizes an image processing algorithm to generate two or more calculated images from base stereopair images, which are the images that one ultimately wants to deliver to the two eyes of the viewer. A first one of those calculated images are sent to a distant display and the other one or more calculated images are sent to one or more transmissive displays placed in front (relative to the viewer position) of the distant display. Each display therefore simultaneously displays the calculated images that each contain at least some of the image information destined for each eye of a viewer. Each display's calculated image, when viewed simultaneously by a viewer, acts as a mask for and combines with the other displayed calculated images, resulting in the two different stereoscopic images being provided to the left and right eyes of the viewer, the stereoscopic effect being caused by the geometry of the spacing of the viewer's eyes and the spacing of the various layered displays. Putilin et al. discloses that the electronic processing to generate the calculated images necessary to deliver each of the base stereopair images to the appropriate eye can be accelerated by an artificial neural network. In one certain embodiments in the patent, multiple transmissive liquid crystal display panels are stacked one behind the other (relative to the viewer) in conjunction with a spatial mask, such as a diffuser, which is placed between liquid crystal displays to suppress Moiré patterns. While disclosing a highly effective imaging system, however, Putilin et al. describes a highly complex system that requires significant power. Thus, it may not be suitable for all purposes, including low cost applications where low-tech and flexible options are desirable.
As such, there remains a need in the art for improved three-dimensional imaging systems and methods that provide high resolution images simply and effectively to users.